Association of C-reactive protein, smoking and metabolic syndrome among the health check-up population

Background: C-reactive protein (CRP) is considered a global inflammatory burden indicator. It was unknown which metabolic syndrome risk factor components could predict CRP levels and possible interaction with smoking in healthy young and elderly Taiwanese. Materials & Methods: We collected totally 6,406 adult subjects (41.4% women) from January to December 2001 from the health screening program in a tertiary hospital in Taiwan. High CRP was classified as more than 5.31 mg/L, which was the 90th percentile cutoff value. Components of metabolic syndrome were defined by the modified Adult Treatment Panel III criteria. Results: There were 13.5% of the study population with age older than 65 years, with 7.2% abstinence and 17.3% current smokers. The average CRP levels, after adjusting for gender and smoking effects, were 3.43 mg/L in young and 4.64 mg/L in elderly population (p < 0.0001). The prevalence rate of metabolic syndrome was 19.4%, higher in elderly than young age (29.1% vs. 17.9%, p < 0.0001). CRP levels were positively related with smoking status. After adjusting for multiple variables such as gender and smoking status, high CRP levels still strongly associated with metabolic syndrome. Conclusions: CRP was significantly associated with smoking and metabolic syndrome. Inflammation, smoking and atherosclerotic risks were interrelated among healthy population in Taiwan.